> Am i correct in assuming that libtiff and IJG jpeg-6a does not support
> jpeg compression for cmyk images?
No, you are not. It should work. I say "should" because we've been
unable to find any other implementations for cross-testing.
If you intend to exchange TIFF/JPEG images with other applications,
you will need to discover whether those apps support the
TIFF Tech Note #2 flavor of TIFF/JPEG.
regards, tom lane
organizer, Independent JPEG Group